Fuel line check valves, by their very nature, are required to be extremely sensitive to fluid pressure differentials. The valve head must have a positive engagement with the seat, in a no flow or reverse flow situation; yet must be weakly biased against the seat, so that a nominal positive fluid pressure differential on the inlet side of the valve assembly will quickly unseat the valve to open fluid communications between the inlet and outlet.
The valve structures commonly employed in the auto industry for relatively small (2.3 liter) engines, generally comprise an elongated chamber in fluid communication with the inlet and outlet having a ball valve mounted on a long relatively weak helical spring. The major problem encountered with this type of an arrangement is that as the ratio of length to diameter (L/D) of the spring increases, the inherent stability of the spring decreases. The instability of the spring leads to buckling of that component, and chatter of the ball valve within the chamber, thereby causing turbulence and less than ideal "open flow" conditions.
To date there has not been devised a fuel line check valve assembly which meets the performance criteria desired while avoiding the problems enumerated, supra. SUMMARY OF THE INVENTION
An object of the present invention is the provision of a fast acting fuel line check valve assembly which has positive seating and provides unrestricted "open flow" conditions.
A further object of the instant invention is the provision of a check valve assembly having a cage element, which acts as a guide for the biasing spring and prevents the buckling thereof.
Another object of the instant invention is the provision of a check valve assembly, which employs a free floating spring biased ball valve, partially contained within an apertured recess in a guide member.
Still another object of the present invention is the provision of a valve assembly, which utilizes a guide element having an orifice in fluid communication with the downstream side of a free floating ball valve, to insure positive seating of the valve head in a reverse flow situation.
Yet another object of the instant invention is the provision of a new and unique valve assembly, which accomplishes all of the objectives stated, supra, while avoiding the problems inherent in the prior art devices.
These and other objects, advantages and novel features of the instant invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.